Read local drive file using web app

Quote:

I have tried many options in HTML and Javascript but could not succeed.

<pre lang="HTML"><button onclick="openFile(dispFile)">Open a file</button>

<script>
            function dispFile(contents) {                
                document.getElementById('contents').innerHTML=contents;
                alert(contents);
            }
            function clickElem(elem) {                
                var eventMouse = document.createEvent("MouseEvents");
                eventMouse.initMouseEvent("click", true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
                elem.dispatchEvent(eventMouse);
            }
            function openFile(func) {
                readFile = function(e) {
                    var file = e.target.files[0];
                    if (!file) {
                        return;
                    }
                    var reader = new FileReader();
                    reader.onload = function(e) {
                        var contents = e.target.result;
                        fileInput.func(contents);
                    }                    
                    reader.readAsText(file);
                }
                fileInput = document.createElement("input");
                fileInput.type='file';
                fileInput.style.display='none';
                fileInput.onchange=readFile;
                fileInput.func=func;
                document.body.appendChild(fileInput);
                clickElem(fileInput);
            }
        </script>